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(No Model.)

H. FfWAITE. ELEGTR-IG DENTAL APPARATUS.

No. 566,103. Patented Aug. 18,1896.

" Nrrnn STATES ATENT rrrreEt HARRY WAlTE, on NEW YORK, NqY,

ELECTRIC DENTAL AP PARATU sr-ncrrrcnrronromin part of Letters Patent No. 566,103, and August is, 1896.

Application no April 16,1896. semi No. 587,842. on model.) I

:"0 alt-mm it may concern.-

Be-lt known that I, HAnnY FULLER WAITE, a citizen of the United States, residing in the city, county, and State of New York, have in- ,vented certain new and useful Improvements in DentalApparatus, of which the following is a specification.

hereinaftermoreparticularly set forth.

Referring to the accompanying drawings, Figure l is a plan view of a box or case, showing the general arrangement'of the apparatus.

Fig. 2 is a longitudinal vertical section of the rheostat. Fig. 3 is a transverse vertical section. of the same. Fig. 4 is a section showing the construction of the switch. Fig. 5 is an enlarged plan view showing the operation of the switch, and Fig. 6 is a general diagrammatic view showing the mode of using the apparatus.

it is well-known that the application ofan electric current to the human body has, under certain conditions,wl1at is generally described.

as a catalytic action producing a cataw phoric efiect, which tends to increase the absorption of fluids by the parts subjected to the action of the current, and this effect has been taken advantageof in dental operationsfor the purpose ofrendering the teeth or gums. insensibl' to pain. It is well known that when cocaine, for instance, is applied to the gum or parts surrounding a'tooth it practically aliects only the external portions of the parts, but it has been found that the application of electricity to the parts tends to cause them to absorb the cocaine and extend its eificiency. Thus, for instance, in filling a tooth, if cocaine is applied to the cavity, in ordinary practice it produces little or no effeet, as it does not seem to penetrate, the tooth sufficiently to produce the effects desired. If, however, when so applied a current of electricity is caused to pass through the tooth in the proper direction, such as is usual in producing the cataphorie eifect, it has been found that the cocaine will extend throughout the mass of the tooth or lie-absorbedin such a way as to permit. the usual dental operations on the most sensitive tooth without painm The object-of my present invention is to provide a dental cataphoric apparatus which shall be well adapted for the. purposes intended, and I will now proceed to describe the general characteristics of theapparatus.

For convenience it is preferable ,to make.

the apparatus portable, and A represents'a suitable case onbox adapted to contain the necessary batteries (not shown) and provided on its top A with a milliamperameter B, a

resistance device C, and. a switch devicel), they being arranged in such relation as to be readily observed and handled in the application of the eleetric.current.

The milliampere-meter LB need not be specifically described, as it is one of usual constrnction, and is used for the purpose-of 'meas.- uring the current withgreat accuracy.

The resistance device 0 requires to be of great sensibility and delicacy in order that the current going to the sensitive tooth can be carefully and delicately regulated, and

some of my improvements relate more particularly' to, the construction and arrange-- ment of the resistancedevice, and will be more particularly described.

' The switch device I) is also the subject ofsome' improvements hereinafter described, and all these improvements combine to make a structure well adapted for the delicate ma-.

nipnlations of the electric current necessary in .dental cataphoric apparatu The resistance device 0 e bodies in its general construction a well-known rheostat, in which there is a base 0, of slate or similar non-conducting material, having a raised portion Chthe surface of which'is covered with .a.conduct-ing material, such as graphite, and

which conducting material is the real resistance material of the rheostat. In orderto make a good connection with the graphite on the raised portion 0 I place thereon a metal plate 0. which is connected to the bindingpost (3. -Mounted on the base :C, near its center,- is a raised bearing 0 on which is mount-ed the standard E, carrying an arm E",

. having a brush or contact-finger E bearing on e scenesortion C. This the surface of standard-and arm {one or are of conducting material and are con t te ith the electric circuit in any suitable way, a binding-post E beingshown bearing on the end of a screw Efiwhich' passes through the standard into the raised bearing 0 The upper portion of the standard is hollowed an'dcontains a spring E and there is a washer E bearing on the spring, and by means of the screw E it will be seen that the standard can be tightly and at the same time accurately adjusted on theraised bearing (1 and be capable of being turned by the thumb and finger to cut in or out a greater or less portion of the graphite surface of the resistance. It happens, however, that when the current is flowing through the sensitive tooth it is desirable to make fine adjustments" of the resistance in the circuit, and for this purpose the standard E is'provided with a worm-wheel e, and arranged to engage with this is a worm e, so that very delicate movements of the arm .E'.-can be obtained. The

worm e may be suitably mounted with relation to the standard, and I have shown a case orcover Fembracing the rheostat, in the walls of which is mounted a shaft F, carrying the worm e. This shaft F is provided with a thumb-nut F extending outside the case F, and it is provided with reduced bearings, permittingit to slide longitudinally in the case.

There is a spring F, surrounding the shaft F,

which tendsto force the worm .3 into en gagement with the worm-wheel e, and when so engaged on turning the'thumb-nut F -the re-- sistance-arm E is movedin accordance therewith. Sometimes it is not necessary to prcvide such accurate adjustment, and I therefore arrange the shaft F so that the worm and worm-wheel may be disengaged, and thus when'tho shaft is drawn outward, as shown in Fig. 3, the latch L, pivoted on the outer side of the case, will fall onto the reduced portion of the shaft and hold the shaft in position with the worm disengaged from the w'ormwheel. When, however, the latch is lifted, the spring F will automatically cause the worm e to engage the worm-wheel e, and the resistance device can be operated by the thumb-nut F In order to show the relative position of the resistance-arm E, Iattach to the stand ard E a pointer I, and arrange this over a graduated scale I, and the whole is prefer- .ably inclosed in the case F by a glass cover F secured in position by a rubber gasket f. With this construction it will be seen that the resistance can be varied either by turning the standard directly to include more or less of the resistance material in the circuit, or when finer adjustments are required by turning the thumb-nut F through the medium of the worm and worm-wheel, a very delicate adjustment of the resistance can be attained.

The switch D is arranged substantially as is common in connection with batteries for it produces a shock which is not onlydis agreeable, butioften injurious, and for this purpose it. has been common to. make the I switch-arm of such form that before leaving one contact it willclose another adjacent contact, and thus prevent an actual break in the circuit. While this accomplishes the result desired, it often happens that through accident or ,0therwise the switch-arm is left in such a'position as to bear on two adjacent contacts, and then the cell or cells included between those contacts are short-circ'uited and'their usefulness soon destroyed. One of the features of my present invention is to provide means for overcoming this objection, and I have shown the arms D D as being provided with a spring-actuated contactpiece. (Shown more particularly in detail in Fig. 4.) Thus the arm D is extended in the form of a socket D, on which is mounted a stem Dgcarrying on its lower face a contact-piece D, having diameters of different lengths; that is to say, its longest diameter is such as to extend a little more than from one contact-piece to the other, while its shortestdiameter'is such as to extend a-little less than the distance from one contact picce to another, as clearly indicated in Fig. 5.

Around the stem 1) is placed a spring (1,

and this is fastened to the stem and to the lever-arm in such a way as to turn the contact-piece so as to have its shortest diameter in line with the contacts d. Pins d take into slots in the socket D and limit the movements of the stem on its longitudinal axis. Thus when the lever Dor D for instance, is to be moved one way or the other to include or exclude more or less of the cells the operator turns the stem 1) so that the contactpiece D is in the position indicated in full lines in Fig. 5 and moves the arm from one contact (1 to another without breaking the circuit, and then when the lever is over-any desired contact-piece he lets go of the stem, when the spring (i will automatically turn the contact-piece D into the position indicated in dotted lines, Fig. 5, and if perchance it should be left in any other than its proper position directly over one of the contacts d it will not complete the circuit between the two adjacent contacts, and all danger of short-circuitin g the battery is avoided.

In Fig. 6 I have shown diagrammatically an arrangement of circuits, in which S is a series of batteries .orcells connected to the contactterminals d, and T represents a tooth being IIC v in g-post.

treated. and are the terminals for the external circuit, and connected to the terminal by a conductor 1 is an electrode 0, in the form of a cap or other device, adapted to fit the top of the tooth T, while P represents anordinary sponge electrode, which may be placed .on the outside of the jaw, and is connected. by a conductor 2 with the'minus bind- This post is connected by a conductor 3 with the rheostat- C, and this by a conductor at with the milliampere-rneter B, and a conductor 5 leads from the latter to the switch-arm D, bearing on one of the contactterlninals (Z, connected to the'battery', while the switch-arm D is shown as bearing on another contact-terminal d and is connected with the plus binding-post bya conductor 6; It will thus be seen that the circuit includes 'a' certain number of battery-cells, a milliamper'e-meter, the resistance, and the tooth or portion of the body being operated upon, and it will also be evident that by observing the usual precautions and adjusting the parts the desired. current can be caused to pass through the tooth, producing the catalytic eitects, and this current can be delicately and accurately manipulated to suit the requirementsof any particular case.

I laving thus described the general principles and characteristics of my invention, it will be understood that the detailsmay be varied by those skilled in the art to adapt it for the particular purposes for which it is desired to use it without departing from the spirit of my invention. 1

What I claim is- 1. A rheostat comprising a resistance medium, .a movable standard for adjustingthe arm, a worm-wheel on the standard, and a,

shaft having a worm to engage the standard, the shaft being provided with means for holding the worm out of engagement with the worm-wheel and including it in engagement when desired, substantially as described.

2( A rheostat comprising a base, a resistance material, an arm moving over the re sistance material, a standard supporting the arm and having a worm-wheel, a case inclosing the resistance material, a shaft mounted in the case and having a worm to engage the worm-wheel, .the 's'pring tending to move the shaft intoengagenient, and a latch to hold the worm out of engagement, substantially as described.

3. A s witoh-ar n provided with a stem car- -ryin g a contactdevicehaving variable diamei ters, a spring controlling the normal position of the contact device with relation to the arm,

and .means permitting a partial rotation of thecontact device, substantially as described.

. 4. In a dental cataphoric apparatus, the

combination of a series of battery cells andcontacts, switch-arms arranged to include more or less of the'cells in circuit, a galva-- nometer in the circuit, an adjustable rheostat also included in the circuit, an electrode adapted to fit a tooth, and an electrode arranged to bear on the jaw, the said electrodes being included in the circuit, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing fwitnesses.

I HARRY F. WAITE. WVitnesses-z WM. H. WoonnnLn, THOMAS DLBAKER- 

